If you have a radeon, and do a fresh install of OS 9, they have the drivers built in. That includes all the way up to the 9xxx series. It's even built in for my MDD 1.25Ghz Dual. If you can, go grab one off of eBay. I think you could do a GeForce 6200 flashed on it. But you will have to do the mod. I doubt it would work on OS 9 though, but you would get nice OS X performance.

Yeah, I would suggest a Radeon over GeForce. more updated, faster and is supported better (if you need drivers, I can show you were to get the modern OS 9 drivers)